A motor vehicle axle, especially the steerable axle of a motor vehicle, usually comprises a lower suspension arm, a longitudinal control arm, and a steering knuckle or shock-absorbing strut, which is fastened rotatably and pivotably to the lower suspension arm. These axle components are usually connected to one another in an articulated manner by means of support joints, and the support joints have support joint pins, which are pressed into a conical bearing eye of the corresponding axle component belonging to them and are secured by means of a lock nut. Such articulated connections are also provided, e.g., between the steering arm of the steering mechanism of a motor vehicle and the tie rod. This articulated connection also has a joint pin, which is pressed, e.g., into the bearing eye of the steering arm and is likewise secured there by means of a nut. Various pressing-out devices, by means of which the corresponding joint pin can be pressed out of the conically tapering bearing eye, have been known for pressing the joint pins out of the corresponding bearing eyes of the support joints or tie rod joints on the motor vehicle axle.
Since the support joints have different dimensions, and the dimensions of the tie rod joints also differ from those of the support joints of the motor vehicle axle, pressing-out devices have been known, which, adjusted corresponding to these dimensions, are designed for the particular use for specific support joints or tie rod joints.
The prior-art pressing-out devices for disassembling a support joint pin or a tie rod joint pin comprise essentially a support element with a receiving fork, a pressing lever, an adjusting member, and a pressing member for actuating the pressing lever.
In a prior-art embodiment of a pressing-out device (FR 2 134 741), the adjusting member is designed as an adjusting spindle and connects the support element to the pressing lever. To set the distance between the support element designed as a support lever and the pressing lever, the adjusting spindle is passed through a central through hole of the pressing lever and is provided with an adjusting nut. At its free end located opposite the adjusting nut, the adjusting spindle has a bearing ring, through which a bearing journal can be passed, on which the support lever is mounted in a limitedly pivotable manner, the bearing journal being arranged firmly seated in the support lever. The support lever is divided into two fork legs and at one of its ends it has a receiving fork of adjustable width, which is used to receive the bearing eye of a support joint or of a tie rod joint. At their ends located opposite the receiving fork, the two fork spars are elastically connected to one another, and this elastic connection area also forms a pressing surface for a pressing screw. The bearing journal, around which the support lever can be pivoted, is provided between this pressing surface and the receiving fork. The pressing lever and the support lever are in one plane during use. A corresponding continuous threaded section is screwed into the pressing lever opposite the pressing surface of the support lever and it can be pressed against the pressing surface of the pressing lever during use, so that a corresponding relative pivoting movement of the support lever to the pressing lever is brought about to press the joint pin out of its bearing eye. The pressing lever is provided with a pressing section, which is located opposite the receiving fork of the support lever at a spaced location therefrom. By adjusting the adjusting nut on the adjusting spindle, the distance between the pressing lever and the support lever is variably adjustable, and the two levers, the pressing lever and the support lever, extending approximately in parallel to one another, can be brought into contact with the bearing eye of the support joint or even the tie rod joint in the preferred pressing-out position. To adjust the receiving fork to the size of the bearing eye, the bearing journal of the receiving fork is designed as an adjusting screw and is mounted firmly seated in a fork spar and is captively secured by a locking ring there. The two fork spars are arranged at spaced locations from one another in the area of the bearing journal, so that the adjusting spindle with its bearing ring is rotatably mounted on the bearing journal between the fork spars. The bearing journal passes through the second fork spar with a threaded section, on which a wing nut is screwed on the outside, by means of which the distance between the two fork spars is variably adjustable. The jaw size of the receiving fork can be adjusted to different dimensions of bearing eyes of support joints or tie rod joints due to its variable adjustability of the distance between the spars of the fork. However, only low stability of the prior-art pressing-out device can be achieved due to the elastic design of the two fork spars, so that extremely firmly seated joint pins cannot be pressed out with the prior-art pressing-out device without damaging the pressing-out device. Further, provisions are made in the prior-art pressing-out device for screwing the pressing screw, turned by 180.degree., into the support lever, rather than in the end of the pressing lever, in which case it the pressing screw! will be supported during pressing out in a corresponding manner at the end of the pressing lever to perform the necessary pivoting movement. As a result, the support lever is additionally weakened in the connection area of the two fork spars, because the through thread for the pressing screw is arranged directly in the elastic connection area of the fork spars. This in turn enables only weak pressing-out forces to be applied with the prior-art pressing-out device.
In another prior-art pressing-out device (FR 2 188 481) a support plate is provided as a support element. The support plate is provided with a plurality of receiving forks of different dimensions. In this prior-art pressing-out device, the pressing lever is pivotably mounted on the adjusting spindle with a bearing journal passing through the pressing lever and the adjusting spindle. The bearing journal is arranged firmly seated in the pressing lever. The distance between the support plate and the pressing lever is adjusted by means of an adjusting nut. The adjusting nut is screwed on the adjusting spindle on the outside. The support plate can be displaced along the adjusting spindle by actuating the adjusting nut. To secure the distance between the support plate and the pressing lever outside of use as well, a coil spring is provided between the two, and the distance set between the pressing lever and the support plate can be maintained by means of the compression coil spring by the pretensioning force of the coil spring outside of use as well.
Even though this prior-art pressing-out device is suitable for certain dimensions of support joints or even tie rod joints for pressing out the joint pin, it has the drawback, due to the dimensions of the support plate, that this prior-art pressing-out device cannot be used in the case of crowded space conditions at a motor vehicle axle. Moreover, this pressing-out device can also be used only for support joints or tie rod joints with the bearing eyes of which one of the three existing receiving forks can be brought fittingly into contact.